Britain to publish much-delayed report on 2003 Iraq war on 6 July

London: Britain's long-delayed mammoth inquiry into its part in the 2003 war in Iraq will be published on 6 July, its chairman revealed Monday.

The Iraq Inquiry headed by former senior civil servant John Chilcot, which began in 2009, was originally due to report within a year.

In a letter to Prime Minister David Cameron on Friday, Chilcot said that routine checks to ensure that the report did not breach national security had been completed, without the need for redactions.

Iraq Inquiry chairman Sir John Chilcot in a file photo. AFP

A 6 July publication date allows time for "final proof reading, formatting, printing and the steps required for electronic publication", he said, in the letter published Monday.

The report is expected to be 2.6 million words long.

The Chilcot inquiry was set up by prime minister Gordon Brown, the successor of Tony Blair, who led Britain into the conflict in 2003. Some 179 British soldiers died in the war.

The inquiry's vast remit was to consider Britain's involvement in Iraq from 2001 to 2009 to establish what happened, the way decisions were made and actions taken, and to identify lessons that can be learned.

It received evidence from over 150 witnesses, held more than 130 sessions of oral evidence, and analysed more than 150,000 government documents.

The report is expected to highlight how Britain's involvement in Iraq — particularly questions over whether Blair's government "sexed up" a dossier on Iraq's weapons of mass destruction to make the case for war — remains the subject of heated debate.

The inquiry's costs to April 2015 were £10.375 million ($15 million, 13.1 million euros).